diff --git a/src/stitching_scanner.py b/src/stitching_scanner.py
index e3fef1a..8c1f484 100644
--- a/src/stitching_scanner.py
+++ b/src/stitching_scanner.py
@@ -342,8 +342,8 @@ class StitchingScanner:
                 # For LEFT scan: frame starts at the transition X position
                 # Compare frame's RIGHT edge with mosaic's transition strip RIGHT edge
                 
-                transition_x_end = min(x_offset + fw, mw)
-                transition_x_start = max(x_offset, transition_x_end - horizontal_overlap)
+                transition_x_end = x_offset
+                transition_x_start = min(x_offset, x_offset - horizontal_overlap)
                 
                 # Y range: within the transition strip area
                 y_start = 0